1. Field of the Invention
The present invention relates to bicycles and more particularly, to a combination buddy bicycle that is designed to be ridden by one to four persons, and can be selectively arranged into a buddy bicycle for riding by two riders in a side-by-side manner, or collapsed to reduce storage space.
2. Description of the Related Art
Many four-seat buddy bicycle designs are known. Exemplars are seen in Taiwan Utility M290839, entitled “Four-wheel buddy bicycle”; Taiwan Utility M312479, entitled “Improved structure of four-wheel buddy bicycle”; Taiwan Utility M322908, entitled “Buddy bicycle steering structure”. These buddy bicycles are designed to be ridden by multiple persons. However, these conventional designs still have drawbacks as follows:    1. These conventional buddy bicycles are commonly huge, heavy and not collapsible for convenient storage. To the manufacturers or distributors, these conventional designs do not facilitate packing or delivery.    2. These conventional buddy bicycles are based on a chain-transmission design. The transmission chain may fall from the chain wheels or break easily if only one of each two side-by-side riders is propelling the bicycle or there is a significant difference between the propelling forces from two side-by-side riders. When this problem occurred, it will be difficult to push the buddy bicycle back home or to the bicycle rental shop for repairmen.    3. When changing the steering direction, the two front wheels are biased synchronously subject to the linking effect of the linking rod between the two front forks of the front wheel unit. Subject to the linking effect of the linking rod, turning the buddy bicycle to a different direction is less stable.    4. The multiple frame components of the buddy bicycle are fixedly connected together by welding. The welding procedure requires much labor and time, and does not meet the principles of environmental protection.
Further, there are known tandem bicycles with fore-to-aft seating arrangement designed to be ridden by one to four persons, or even more than four persons. The term tandem refers to the seating arrangement. This fore-to-aft seating arrangement does not facilitate interaction, losing the fun of bike pool. Further, the more the number of riders of a tandem bicycle the higher the difficulty level will be.
Further, there are known face-to-face tandem bikes that allow two riders to ride the tandem face to face or back to back. However, a rider or person sitting on a tandem in the reversed direction, the rider may suffer from dizziness or motion sickness